In recent years, studies have been intensively carried out for a light emitting device that uses, as illumination light, fluorescence emitted from a light emitting section which includes fluorescent material. The light emitting section emits the fluorescence upon irradiation with excitation light, which excitation light is emitted from an excitation light source. A semiconductor light emitting element is used as the excitation light source, such as a light emitting diode (LED), a laser diode (LD), or the like.
Patent Literatures 1 and 2 each disclose a lamp as examples of techniques related to such a light emitting device. In order to achieve a high-luminance light source, the lamps disclosed in Patent Literatures 1 and 2 employ a laser diode as the excitation light source. Laser beams emitted from the laser diode are coherent light; these laser beams have strong directivity, and therefore can be converged and used as the excitation light without waste. A light emitting device using such a laser diode as the excitation light source is suitably applicable for vehicle headlamps.
Meanwhile, Non Patent Literature 1 discloses a vehicle headlamp as an example of a technique for achieving a vehicle headlamp that employs an incoherent white LED.